Depends on the squadron, and its leave policy... if their policy is phone checkout, then shouldnt be a problem. In some squadrons its not a big deal to checkout after your last event of the day. If it was me I wouldnt try to checkout any earlier then 1400 or 1430 if this was the case (and I were flying out of CRP) and made sure i had a change of clothes in the car so I could just go directly to the airport.